Re: Performance degradation with FFSB between 2.6.20 and 2.6.21-rc7

[Valerie Clement <valerie.clement@bull.net>]

Jens Axboe wrote:
> On Thu, Apr 19 2007, Valerie Clement wrote:
>> Jens Axboe wrote:
>>> On Thu, Apr 19 2007, Valerie Clement wrote:
>>>> Jens Axboe wrote:
>>>>> Please tell me how you are running ffsb, and also please include a
>>>>> dmessg from a booted system.
>>>>>
>>>> Hi,
>>>> our mails crossed! please see my response to Andrew.
>>>> You could reproduce the problem with dd command as suggested, it's more 
>>>> easy.
>>>> I'm sending you the dmesg info. For my tests I used the scsci sdc device.
>>> Thanks, it does. Can you try one thing for me? If you run the test on
>>> sdc, try doing:
>>>
>>> # echo 64 > /sys/block/sdc/queue/iosched/quantum
>>>
>>> and repeat the test.
>>>
>> OK, that's done.
>>
>> With the change of quantum, the throughput scores are now a little bit 
>> better in 2.6.21 than in 2.6.20.
> 
> Wonderful, now try the patch I sent in the next mail and repeat the
> test.
> 

That's done too.
Now I've got the same results in 2.6.21 as in 2.6.20.
Thanks,

   Valérie